Blood Tests While Taking Essential Phospholipids: What to Check and When
Essential phospholipids are sold across Europe as liver-support products, and many gym-goers take them "just in case". Yet a capsule cannot tell you how your liver is actually doing. Only laboratory tests can. Our editorial team explains which markers are worth checking before and during a course, how to read them sensibly, and why training itself can distort the picture.
What essential phospholipids are and why testing matters
Essential phospholipids (often abbreviated EPL) are a purified fraction of soya lecithin rich in polyenylphosphatidylcholine. The idea behind them is simple: phosphatidylcholine is a major building block of cell membranes, including those of liver cells, so supplying it from outside might help damaged hepatocytes repair themselves. In parts of continental Europe these products are licensed medicines; in the UK, comparable soya lecithin and phosphatidylcholine products are generally sold as food supplements.
The evidence base is mixed. A review by Gundermann and colleagues summarised decades of mostly small studies suggesting improvements in liver enzymes and fatty change, while a later systematic analysis in non-alcoholic fatty liver disease found modest benefits but highlighted the low quality of many trials. In short, EPL are plausible but not a proven cure.
That uncertainty is exactly why testing matters. If you take a liver product without baseline data, you have no way of knowing whether it helped, whether there was a problem in the first place, or whether something more serious is developing in the background. Abnormal liver tests have dozens of possible causes, from fatty liver and alcohol to viral hepatitis, medicines and inherited conditions.
A sensible approach is to treat EPL as one small tool and laboratory monitoring as the real safety net. In practice, this means a set of tests before you start, a repeat after a defined period, and a clear plan for what to do if results move in the wrong direction.
The core panel: liver function tests
In the UK, a "liver function test" (LFT) panel ordered by a GP usually includes alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin and albumin, with gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST) added in some laboratories or on request. British Society of Gastroenterology guidance on abnormal liver blood tests recommends interpreting these values together rather than reacting to a single number.
| Marker | What it mainly reflects | Notes for active people |
|---|---|---|
| ALT | Damage to liver cells | Can rise after very hard training, though less than AST |
| AST | Liver and muscle cell damage | Often elevated after heavy lifting; not liver-specific |
| GGT | Bile ducts, alcohol, enzyme induction | Useful to separate liver from muscle sources |
| ALP | Bile flow, bone turnover | Higher in teenagers and with bone growth or injury |
| Bilirubin | Processing of haemoglobin breakdown products | Mild isolated rises are often Gilbert’s syndrome |
| Albumin | Liver synthetic capacity | Usually normal unless disease is advanced |
ALT is the most liver-specific of the routine enzymes, so it is the one most people track when taking a liver-support product. A falling ALT in someone with fatty liver can be encouraging, although it may equally reflect weight loss, less alcohol or simply normal variation between measurements.
GGT deserves attention in anyone who drinks regularly or takes medicines that induce liver enzymes. It also helps answer the classic athlete question: if AST and ALT are both raised but GGT is normal, a muscular rather than hepatic origin becomes more likely.
Bilirubin and albumin are less likely to change during a supplement course, but they complete the picture. A rising bilirubin with dark urine or yellowing of the eyes is a reason to stop self-treatment and see a doctor promptly.
Beyond the liver: lipids, glucose and kidney markers
Fatty liver rarely exists in isolation. It is closely linked to insulin resistance, abdominal fat and abnormal blood lipids, and EASL–EASD–EASO guidance treats it as part of a wider metabolic picture. That is why a useful testing plan goes beyond enzymes.
- Lipid profile: total cholesterol, LDL, HDL, triglycerides and non-HDL cholesterol.
- Glucose control: fasting glucose or HbA1c, the latter commonly used in UK primary care.
- Kidney function: creatinine and eGFR, keeping in mind that muscular people often have higher creatinine.
- Full blood count: a low platelet count can be an early hint of more advanced liver disease.
- Creatine kinase (CK): helpful when you suspect training is inflating AST and ALT.
Some EPL studies have reported small improvements in triglycerides and cholesterol, but the effects are inconsistent and much smaller than those of diet, weight loss or lipid-lowering medication. Tracking lipids is therefore less about proving the supplement works and more about understanding your overall cardiometabolic risk.
If a GP finds persistently raised liver enzymes, they may also arrange a non-invasive fibrosis assessment, such as the FIB-4 score calculated from age, AST, ALT and platelets, or an Enhanced Liver Fibrosis (ELF) blood test, which is used in many NHS pathways.
Hepatitis B and C serology, iron studies and, depending on history, autoimmune markers can be part of a wider work-up. These are not tests to order on a whim, but they explain why "taking something for the liver" should never replace a proper diagnosis.
How training can distort your results
Heavy resistance training damages muscle fibres in a controlled way, and those fibres release enzymes into the bloodstream. A frequently cited Swedish study by Pettersson and colleagues showed that healthy men who began weightlifting developed AST and ALT values that would look alarming on a standard liver report, with CK rising dramatically at the same time.
The practical lesson is to avoid hard sessions for at least two or three days, ideally longer, before a blood test. Report your training habits to whoever interprets the results so that raised enzymes are not automatically blamed on the liver.
Dehydration, recent illness, alcohol in the preceding days and certain medicines, such as some painkillers, antibiotics and statins, can also shift values. Standardising conditions — similar time of day, similar training load beforehand, no alcohol — makes before-and-after comparisons far more meaningful.
Finally, people who use anabolic steroids or other unlicensed performance-enhancing substances face a genuine risk of drug-induced liver injury. No supplement neutralises that risk, and honest disclosure to a clinician is the only way to get an accurate assessment.
A practical testing timeline
There is no official monitoring schedule for EPL because they are generally regarded as low-risk. However, a reasonable structure based on general clinical practice for monitoring abnormal liver tests looks like this.
- Baseline: LFTs including GGT, lipid profile, HbA1c, full blood count and kidney function before you start.
- Interim check: after roughly 8–12 weeks, under the same conditions as the baseline sample.
- Ongoing: repeat every few months only if values were abnormal or your doctor advises it.
- Urgent review: jaundice, dark urine, pale stools, persistent itching or right-sided abdominal pain need prompt medical attention regardless of the schedule.
Side effects of EPL are generally mild, most often digestive upset, soft stools or bloating. Anyone with a soya allergy should avoid soya-derived products altogether.
If your enzymes were already high before starting, the key question is why. In the UK, a GP is the right first port of call, and NHS pathways exist for investigating persistently abnormal results. A supplement should never delay that process.
Conclusions of the editorial team
Essential phospholipids may offer modest support in fatty liver, but the research is not strong enough to rely on them as a treatment. What genuinely protects your liver is knowing your numbers and acting on them.
A baseline panel of liver enzymes, lipids, glucose markers and a full blood count, repeated under standardised conditions, gives you far more information than any capsule can. Remember that hard training can inflate AST and ALT, so plan your test days accordingly.
Persistently abnormal results deserve a medical work-up rather than more supplements. That is where the real answers lie.
For further reading, see our articles on how to interpret creatine kinase in strength athletes, on fatty liver and body composition, and on ursodeoxycholic acid.
References
- Gundermann KJ, Kuenker A, Kuntz E, Droździk M. Activity of essential phospholipids (EPL) from soybean in liver diseases. Pharmacol Rep. 2011;63(3):643–659.
- Dajani AI, Popovic B. Essential phospholipids for nonalcoholic fatty liver disease associated with metabolic syndrome: a systematic review and network meta-analysis. World J Clin Cases. 2020;8(21):5235–5249.
- Newsome PN, Cramb R, Davison SM, et al. Guidelines on the management of abnormal liver blood tests. Gut. 2018;67(1):6–19.
- European Association for the Study of the Liver (EASL), European Association for the Study of Diabetes (EASD), European Association for the Study of Obesity (EASO). EASL–EASD–EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease. J Hepatol. 2016;64(6):1388–1402.
- Kwo PY, Cohen SM, Lim JK. ACG Clinical Guideline: evaluation of abnormal liver chemistries. Am J Gastroenterol. 2017;112(1):18–35.
- Pettersson J, Hindorf U, Persson P, et al. Muscular exercise can cause highly pathological liver function tests in healthy men. Br J Clin Pharmacol. 2008;65(2):253–259.
